The continuation of this program will include three major lines of research. 1) The influence of nutritional variables on both development and later behavior. This laboratory has had a continuing interest in studying the effects of early malnutrition and other dietary deficiencies, i.e. iron deficiency, on both development and the long-term effects of these variables. Recently we have developed sensitive tasks, i.e. pituitary-adrenal responsivity to consummatory behavior, which appear to be able to discriminate between some classes of nutritional deficiencies. We propose to continue our investigations on protein calorie malnutrition imposed early in development upon the long-term ability of organisms to use appropriate cues to modify the stress response. 2) The second major line of research involves the use of inbred strains of mice to examine the role of maternal mediation in the effects of infantile stimulation on later behavior. Since we have demonstrated that the mothers of C57Bl/6J strain and A/Jax strain show markedly different behavioral responses following stimulation of their pups, we now have an interesting model to look at the possible phenotypic differences following infantile stimulation as a consequence of the different behavioral responses of the mother. Further studies on the role of infantile stimulation and the development of temperature regulation are also contemplated. 3) The third area of research in this laboratory is related to studies of attachment and the ultimate effects of disturbances in attachment relationships using primates. Studies using the squirrel monkey have been performed using only brief periods of separation. These periods of separation will be extended to more closely examine the relationship between the physiological responses to separation and the behavioral consequences. In the rhesus monkeys we propose to examine the relationship of separation under conditions of either being alone or with a member of the peer group, or with an older sibling, to determine whether there are ways to modify the effects of separation and the subsequent effects of separation when reunited with the mother. Ultimately, it is hoped that we can produce sufficient offspring to do detailed studies on the development of the pituitary-adrenal system in primates.